Showing items 1 - 20 of 41

Your selections:

Yield response from the catalytic conversion of Parsley seed oil into biodiesel using a Heterogeneous and Homogeneous catalyst

Water and Wastewater Digital Surveillance 1 for Monitoring and Early Detection of 2 the COVID-19 Hotspot: Industry 4.0

  • Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Kinuthia, Cecilia Njenga , Ngila, Jane Catherine
  • Date: 2022
  • Subjects: Epidemiology , Monitoring , Pathogens
  • Language: English
  • Type: Journal articles
  • Identifier: http://hdl.handle.net/10210/493539 , uj:45114 , Citation: Matheri, A.N., Belaid, M., Njenga, C.K. and Ngila, J.C., 2022. Water and wastewater digital surveillance for monitoring and early detection of the COVID-19 hotspot: industry 4.0. International Journal of Environmental Science and Technology, pp.1-18.
  • Description: Abstract: There are a high number of COVID-19 cases per capita in the world that goes undetected including clinical diseases compatible with COVID-19. While the presence of the COVID-19 in untreated drinking water is possible, it is yet to be detected in the drinking-water supplies. COVID-19 viral fragments have been found in excrete, this call for wastewater monitoring and analysis (wastewater surveillance) of the potential health risk. This raises concern about the potential of the SARS-CoV-2 transmission via the water systems. The economic limits on the medical screening for the SARS-CoV-2 or COVID-19 worldwide are turning to wastewater-based epidemiology as great potential tools for assessing and management of the COVID-19 pandemic. Surveillance and tracking of the pathogens in the wastewater are key to the early warning system and public health strategy monitoring of the COVID-19. Currently, RT-qPCR assays is been developed for SARS-CoV-2 RNA specimen clinical testing and detection in the water system. Convectional wastewater treatment methods and disinfection are expected to eradicate the SAR-CoV-2. Chlorine, UV radiation, ozone, chloramine is been used to inactivate and disinfect the water treatment system against the SARS-CoV-2. Water management and design of the water infrastructure require major changes to accommodate climate change, water cycle, reimaging of digitalization, infrastructure and privacy protection. The water digital revolution, biosensors and nanoscale, contact tracing, knowledge management can accelerate with disruption of the COVID-19 outbreak (water-health-digital nexus).
  • Full Text:

Waste to energy bio-digester selection and design model for the organic fraction of municipal solid waste

Volatile organic compounds- biodiesel thermodynamic interactions: influence of temperature

Volatile organic compounds abatement : a critical discussion of destruction techniques

  • Authors: Muzenda, Edison , Belaid, Mohamed
  • Date: 2013
  • Subjects: Volatile organic compounds , Bioreactors
  • Type: Article
  • Identifier: uj:4968 , http://hdl.handle.net/10210/13069
  • Description: This paper critically discusses volatile organic compounds destruction techniques. The methods discussed are thermal and recuperative oxidation, catalytic oxidation, regenerative oxidation, flares and bioreactors. Examples of bioreactors discussed are bio-filters, bio-trickling filters and bio-scrubbing filters. The principle of operation as well as the strength and weaknesses of each methods are given.
  • Full Text:

The role of trace elements on anaerobic codigestion in biogas production

The removal of Ni, Cu & Fe from a mixed metal system using sodium hypophosphite as a reducing agent

The effect of leaching time and ammonia concentration on the atmospheric leaching of copper

The effect of leaching time and ammonia concentration on the atmospheric leaching of copper

  • Authors: Ntuli, Freeman , Muzenda, Edison , Ramatsa, Ishmael , Belaid, Mohamed , Kabuba, John
  • Date: 2011
  • Subjects: Copper recovery , Leaching , Ammonia concentrations
  • Type: Article
  • Identifier: uj:5319 , ISSN 2010-4618 , http://hdl.handle.net/10210/8195
  • Description: The effects of ammonia concentration and leaching time were investigated to determine the optimum leaching conditions. The experiments were conducted in a leaching cell submerged in a water bath, with ammonia concentrations of 1.5 M, 2.0 M, 2.5 M and 3.0 M and varying leaching time from 0 to 300 min. Ni-Cu matte containing 23% by mass Cu was used in this experimental study. Increase in the concentration of the lixiviant was found to increase recovery when leaching for 130 minutes, with a recovery of 32.86% Cu using 3 M solution of ammonia. An increase in the leaching time resulted in more copper being leached for all lixiviant concentrations. However, leaching with 2 M ammonia solution gave a higher yield of copper compared to higher concentrations. This anomaly could be a result of cementation; Cu is displaced by Ni as Ni is a more electronegative metal than Cu .It was found that at higher concentrations more nickel was extracted.
  • Full Text:

The development of a Waste Tyre Pyrolysis production plant business model for the Gauteng Region, South Africa

  • Authors: Nkosi, Nhlanhla , Muzenda, Edison , Mamvura, Tirivaviri A. , Belaid, Mohamed , Patel, Bilal
  • Date: 2020
  • Subjects: Batch pyrolysis , Business model , South Africa
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/457906 , uj:40651 , Nhlanhla, N., et al.: The development of a Waste Tyre Pyrolysis production plant business model for the Gauteng Region, South Africa.
  • Description: Abstract: Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks to critically evaluate the feasibility of constructing and operating a waste tyre processing facility and then subsequently marketing and selling the pyrolysis secondary end products by developing a financial business model. The model encompasses costing, procurement, installation, commissioning, and operating a batch pyrolysis plant in Gauteng, South Africa. To achieve the study objectives, an order of magnitude costing method was used for model construction. The results showed the feasibility and sustainability of operating a 3.5 tonne per day batch waste tyre pyrolysis plant in Gauteng Province, South Africa, with a 15-year life span and a projected payback period of approximately 5 years. It was concluded that for the pyrolysis plant to be successful, further treatment steps are required to improve the process economics; also, a stable and sustainable product market should exist and be regulated in South Africa.
  • Full Text:

Reflecting on waste management strategies for South Africa

  • Authors: Muzenda, Edison , Belaid, Mohamed , Mollagee, Mansoor , Motampane, Ntemi , Ntuli, Freeman
  • Date: 2011
  • Subjects: Waste management - South Africa
  • Type: Article
  • Identifier: uj:4710 , ISSN 2078-0966 , http://hdl.handle.net/10210/10956
  • Description: The energy crisis, global warming and a cleaner environment are arguably amongst the most pressing issues at present facing modern society. Before devising a suitable strategy to convert a proportion of the waste into useful product, categorization of waste types is of great significance to any more detailed study. The population of the world continues to grow, as does the average standard of living, increasing demand for food, water and energy which places increasing pressure on the environment. This paper attempts to parameterize waste generation within a South African context in order provide a theoretical foundation for such work to take place. Organic materials, which includes wood, leaves, grass, food, paper, plastic, cotton, synthetic fabrics, sewage sludge, animal remains, bacteria, any carbohydrates or hydrocarbons. These are all materials sent to landfills (with the exception of metal, ceramics and glass). The Gauteng province was chosen for this preliminary study as it constituted 42% of SA’s waste in 2010 making it by far the country’s biggest waste generator. The types of waste that were particularly targeted in lieu of the downstream research endeavoured were medical waste, plastics, tyres and sewage sludge.
  • Full Text:

Recovery of aluminium oxide from flint clay through H2SO4 leaching

Potential and technical basis for utilising coal beneficiation discards in power generation by applying circulating fluidised bed boilers

  • Authors: Belaid, Mohamed , Falcon, Rosemary , Vainikka, Pasi , Patsa, Kamohelo V.
  • Date: 2013
  • Subjects: Coal , Discard coal
  • Type: Article
  • Identifier: uj:4977 , http://hdl.handle.net/10210/13078
  • Description: Coal continues to remain South Africa’s prime energy source with coal fired power generation by ESKOM (62 %) and gasification by SASOL (23 %) leading local coal consumption. Beneficiated coal is also exported (70 million tonnes) while raw sized coal is also consumed for cooking and heating in South Africa’s townships. Discard coal is currently being produced at annual rates in excess of 60 million tonne per annum. This is estimated to have already accumulated to more than 1-billion tonnes. Discard coal is a major concern to the department of mineral and energy regarding the potential environmental impact in the future. It should also be seen as a major resource that could provide economic opportunity. The purpose of this paper is to estimate the production and reservoir volumes of SA coal discards and their technical and economic potential application in large scale power generation through CFB combustion. It was found that whilst discard is a poor material, its varying range in heating value and current production rate makes it a potentially viable material for beneficiation towards electricity generation. It’s been found that beneficiating discard coal could come with some challenges e.g initial costs, but on the other hand it could present techno economic opportunities e.g harnessing new technologies to create employment...
  • Full Text:

Phase equilibrium of volatile organic compounds in silicon oil using the UNIFAC procedure : an estimation

  • Authors: Muzenda, Edison , Simate, Geoffrey S. , Belaid, Mohamed , Ntuli, Freeman , Mollagee, Mansoor
  • Date: 2011
  • Subjects: Phase equilibrium , Thermodynamic models , Volatile organic compounds , Polydimethylsiloxane , Silicon oil
  • Type: Article
  • Identifier: uj:4699 , http://hdl.handle.net/10210/10934
  • Description: This paper focuses on the phase equilibrium of volatile organic compounds in silicon oil chemically known as PDMS (polydimethylsiloxane) at infinite dilution. Measurements can be expensive and time consuming, hence the need for thermodynamic models which allow the calculation of the phase equilibrium behavior using a limited number of experimental data. The objective of this study was to predict infinite dilution activity coefficients of selected VOCs (volatile organic compounds) in PDMS using the Original UNIFAC model. The predicted results show that PDMS can be used to abate volatile organic compounds from contaminated air streams. The results obtained in this work are comparable to those obtained by the same authors through measurements such as the static headspace and the dynamic gas liquid chromatographic techniques as well as other literature. Although the UNIFAC group contribution method over estimate the infinite dilution activity coefficients, the results of this work may be applied in preliminary phases of process design, simulation and feasibility studies.
  • Full Text:

Performance of sodium mercaptobenzothiazole (NMBT) collector on the flotation of Black Mountain ore

  • Authors: Ikotun, Adeshina G. , Muzenda, Edison , Ntuli, Freeman , Belaid, Mohamed
  • Date: 2012
  • Subjects: Black Mountain ore , Copper metal , Sodium mercaptobenzothiazole
  • Type: Article
  • Identifier: uj:4689 , http://hdl.handle.net/10210/10478
  • Description: This paper investigated the performance of Sodium Mercaptobenzothiazole (NMBT) as a collector in the flotation of Black Mountain ore. The ore contains metals such as lead, copper and zinc and the associated minerals of economic importance are chalcopyrite, galena and sphalerite respectively, with traces of silver. The study evaluated the effectiveness of the collector and how pH affects the recovery of minerals in particular copper. The performance of the collector was influenced by mineral surface chemistry. The experimental test work was conducted at varying pH levels using Denver flotation cell in order to investigate the collector performance in a basic medium. The experiments were conducted at two different test runs of slightly basic solutions of pH 8.5 and 9.0. The results of both fresh ore and floated ore samples were analysed using XRF. Although Black mountain ore contains small quantities of copper as compared to other ores, a significant amount w recovered (±78% of the available copper in the ore), as an indication of the performance of NMBT.
  • Full Text:

Organics – biodiesel systems phase equilibrium computation : part 1

  • Authors: Nkosi, Nhlanhla P. , Mokoena, Phumzile , Muzenda, Edison , Belaid, Mohamed
  • Date: 2011
  • Subjects: Activity coefficient , Group contribution , Phase equilibrium , Solubility , Volatile organic compounds
  • Type: Article
  • Identifier: uj:4675 , http://hdl.handle.net/10210/10444
  • Description: The group contribution concept can be applied in the estimation of thermodynamic properties of pure compounds and mixtures. The Modified UNIFAC (Dortmund) is a successful and well-known group contribution model for phase equilibria prediction. In this paper the application of this model to the phase equilibrium of biodiesel - volatile organic compounds systems was tested. Infinite dilution activity coefficients of 30 selected volatile organic compounds (VOCs) in methyl linoleate and methyl palmitate were estimated. The VOCs groups covered in the selection were alkanes, alkenes, alkynes, aromatics, ethers and ketones. The estimated phase equilibrium is favourable for the absorption of these organics into methyl linoleate. The solubility was found to decrease with increase in molecular weight of the VOCs in each group. Saturation was also found to have an effect on solubility. Experimental data are often not available, at least for preliminary design and feasibility studies of absorption processes, group contribution methods can be utilized to predict the required phase equilibria.
  • Full Text:

Optimization of process parameters for castor oil production

Optimization of Biogas Production from sewage sludge

Multi-criteria analysis of different technologies for the bioenergy recovery from OFMSW

Modelling the kinetic of biogas production from co-digestion of pig waste and grass clippings

  • Disclaimer
  • Privacy
  • Copyright
  • Contact